1. Field of the Invention
The present invention relates to a mobile communication system, and more particularly to a signal supply apparatus in a system that can provide both public and private mobile communication services.
2. Description of the Prior Art
In a general mobile communication system, a base station controller (BSC) receives a reference clock signal from a satellite, and synchronizes its internal equipment. For instance, the BSC provides a link between the BSC and a mobile switching center (MSC), a link between the BSC and a base transceiver subsystem (BTS), and a vocoder. In order to receive the reference clock from the satellite, a global positioning system receiver (GPSR) is mounted in the respective BSCs and BTSs, respectively. The GPSR receives GPS information that includes the reference clock and time of day (TOD) information from the satellite, and provides the GPS information to the corresponding equipment.
As described above, in order to receive the reference clock, the GPSR should be mounted on the respective BSCs and BTSs. However, if it is possible to supply the GPS information including at least the reference clock to the respective BTSs that belong to the BSC in a state that the GPSR is mounted only in the corresponding BSC, the system cost can be reduced. Also, if it is possible to supply the GPS information including at least the reference clock to the BSC and BTS using the existing lines, the cost of system installation can be reduced.
U.S. Patent Application Publication No. 2001/0046215 to Kim pertains to a public/private mobile telephone system where only pBSC 203 has a GPS receiver. However, Kim '215 does not teach relaying the date and time information received by the GPS receiver over a LAN cable to a large plurality of Internet protocol private base transceiver subsystems to run a clock in these Internet protocol private base transceiver subsystems, thereby avoiding the need of many GPS receivers.
U.S. Patent Application Publication No. 2001/0024455 to Thaler et al. teaches distributing a reference time signal throughout a IEEE 1394 network. Thaler '455 contemplate receiving the reference signal from GPS. Non 1394 networks are also contemplated. Thaler '455 teaches that the network may be wired or wireless. An 8 kHz clock is contemplated in FIG. 4. Thaler '455 also teaches distribution of the time reference signal over a LAN.
U.S. Patent Application Publication No. 2002/0072381 to Becker et al, teaches transmission of time synchronization signals from one base station to another in a mobile telephone communication system. Becker '381 seeks to do this to reduce the costs of having numerous GPS receivers in a mobile phone system. The synchronization signals are transmitted by wireless communications.
However, I have not seen the transmission of time and date signals received from a GPS receiver to a large number of private base transceiver subsystems in a public/private mobile communications system. Further, I have not seen the transmission of GPS time and date information over a LAN cable to a large number of private base transceiver subsystems. Further, I have not seen the transmission of GPS time and date signals to recipient private base transceiver subsystems to generate a plurality of internal clocks in these private base transceiver subsystems where the private base transceiver subsystems do not have a GPS receiver or a GPS antenna.